The present invention relates broadly to casing boards for use as information displaying and storage devices and, more particularly, to a casing board for use as an information and storage device having a transparent outer layer attached to a substrate with a turned-edge corner.
Casing boards are used for the formation of ring binders, paper holders, videocassette and other information media storage containers and game boards. A casing board is characterized by a generally flat, usually rectangular substrate covered with vinyl or some other suitable outer covering material. The board may be folded into a book-like configuration to form a binder and walls may be affixed thereto to form the casing board into a box. A casing board thus folded defines inner and outer surfaces and the inner surfaces may be fitted with dedicated arrangements to retain specific information bearing media, such as audiotape cassettes, CDs and videocassettes. The more common usage for a casing board folded in a book-like manner is the classic ring binder for holding loose-leaf paper sheets. There, a ring assembly with selectively actuable split rings is attached to a spine whereby the paper leaves may be held in place with the rings latched in a closed disposition.
Developments with regard to the casing board include the disposition of a transparent outer layer on the covered substrate with at least one portion of the transparent outer layer open to form an access opening whereby individual sheets of indicia bearing members may be inserted and interchanged. The uses for such a device are many and varied. They include videocassette storage boxes, study guides, CD-ROM storage boxes, personal ring binders and other forms of information media storage.
Currently, the construction of such binders is generally satisfactory but leaves room for improvement. Typically, a three-piece substrate is formed with a front leaf, a spine portion, and a back leaf arranged in a linear array. An opaque vinyl cover is applied as the primary cover to the substrate and a transparent vinyl cover is applied on the outer surface with the edges and the interstices between the substrates being joined by RF welding. This technique has become the industry standard. The RF welding technique requires shielding and the three-piece substrate because the welding cannot be accomplished through the chipboard substrate. Further, the RF weld technique has an inherent dwell time of three seconds wherein the product must be in contact with the welding mechanism for the three seconds which slows manufacture. As may be appreciated by those skilled in the art, such binders are manufactured on a traveling assembly line and the dwell time of three seconds can accumulate due to the number of binders produced at once.
Another problem associated with the vinyl is its tendency to expand and contract with temperature. The vinyl expands and strains the RF welds and in turn becomes wrinkled, an occurrence which is aggravated by the cooling process. Eventually, the vinyl transparent covers become unsightly due to the temperature responsiveness of the material. Further problems occur when printing on the information bearing members which must come into contact with the transparent vinyl. When the vinyl comes into contact with typical printed material, it tends to pick up the print and produce an image, known as an "offset image," on the transparent vinyl material. This becomes unsightly when the indicia bearing member is to be changed and the print can stick to the transparent vinyl which makes the indicia bearing member difficult to remove, and, once removed, any remaining printed matter on the transparent cover can interfere with newly inserted indicia bearing members.
Finally, the RF weld technique results in a characteristic weld bead around the perimeter of the casing board which presents a less-than-neat appearance and can be sharp, thus presenting a personnel hazard. Finally, once the useful life of the vinyl casing board has passed, the vinyl is not susceptible to current recycling techniques.
In the area of ring binders, the ring latch assembly must be attached to the vinyl substrate with rivets, thus preventing the use of the spine portion as a pocketed portion for receiving individual indicia bearing members.
Therefore, there exists a need in the industry for an improved transparently sleeved casing board.